Air introduction device for use in a transfusion set



July 22, 1969 YOSIAKI WADA AIR INTRODUCTION DEVICE FOR USE IN ATRANSFUSION SET 5 Sheets-Sheet 1 Filed May 27. 1966 y 1969 YQOSIAKI wAbA3,456,647

AIR INTRODUCTION DEVICE FOR USE IN A TRANSFUSION SE'R Filed May 27, 19665 Sheets-Sheet 73 July 22, 1969 YOSIAKI WADA 3,456,647

AIR INTRODUCTION DEVICE FOR USE IN A TRANSFUSION SET Filed May 27, 19663 Sheets-Sheet 8 United States Patent U.S. Cl. 128214 2 Claims ABSTRACTOF THE DISCLOSURE An air introduction device for use with a transfusionset having a hollow cylindrical supporting member whose bottom end isopen but whose top end is provided with a transversely disposed topWall; a hollow needle is supported at its base end by means of passingthrough the top wall, and a block-like piece is fitted rather snuglyinside of the supporting members in spaced relation from the top wall;the piece is provided with an indirectly routed capillary passage foreff cting communication between the space above said piece and the openlower end of said supporting member.

This invention relates to a device for introducing air into atransfusion set. More specifically, this invention relates to a devicefor introducing air into the vessel containing the liquid to betransfused, thereby to maintain the pressure in the vessel so as to makepossible the smooth transfusion from the vessel into the body of man oranimal of the liquid to be transfused.

As an instrument for infusing a liquid such as blood, blood serum,nutrient liquid, etc., into the body of man or animal, a transfusion sethas ben used heretofore, consisting of a vessel for the liquid to betransfused, a glass tube for introducing air, a needle for introducingair, a liquid discharge needle, a dropping or conducting tube and aliquid infusion needle. The vessel which holds the liquid therein with aspace left at its upper part is one which is installed with the glasstube for introducing air and is closed with a stopper. The needle forintroducing air is inserted in such a fashion that its tip piercesthrough the foregoing stopper at the point where the foregoing glasstube is installed so as to be positioned in the inside of the glasstube. The liquid discharge needle, on the other hand, is inserted sothat its tip pierces the aforesaid stopper at another point and becomespositioned inside the liquid to be transfused. The dropping tube andinfusion needle are connected with the liquid discharge needle. Incarrying out the transfusion, an assembly so composed is used turnedupside down. (This type of transfusion set will be described later withreference being had to the accompanying drawing.)

The conventional transfusion set such as hereinabove described has,however, the following drawbacks; (1) The vessel for holding the liquidto be transfused are available in various capacities depending upon theliquid to be transfused, and hence there was the inconvenience that thediameter and length of the glass tube for introducing air must bechanged accordingly. (2) The installation of the glass tube forintroducing air in the vessel not only involved much labor and equipmentfor such as washing and "ice sterilizing the tube and accomplishment ofa tight closure, but the possibility of contamination of the liquid tobe transfused by entry of foreign matter is also exceedingly great. (3)For preventing of damage to the glass tube for introducing air and itsfalling out from the stopper, great care is required in moving thevessel or its storage.

Thus, the drawbacks of the conventional transfusion set were caused bythe fact that the glass tube for introducing air was held as being anindispensable part of this set. Accordingly, an attempt was made to usea vessel not having a glass tube for introducing air, filling thisvessel with the liquid leaving a space at the top and reducing thepressure of this space. However, since a special equipment was re quiredto attain the reduced pressure it was not entirely satisfactory.

Therefore, the object of this invention is to provide a transfusion setwhich does not require the use of a glass tube for introducing air northe use of reduced pressure.

The foregong object of this invention is achieved by using instead ofthe glass tube for introducing air and the needle for introducing air inthe hereinbefore-described known transfusion set, an air introductiondevice comprising a cylindrical supporting member open at its bottom buthaving a ceiling at its upper end, a hollow needle whose hollow portionforms an air passage communicating with the interior of said supportingmember, whose base is supported by means of the aforesaid ceiling, andwhich protrudes upwardly above the aforesaid supporting member axiallythereof, and a piece fitted inside the aforesaid supporting memberspaced apart from the inner surface of the aforesaid ceiling foreffecting the communication between the aforesaid space and the open endof the supporting member by way of a confined air passage, characterizedin that the aforesaid confined air passage has such a small diameter asto be capable of substantially preventing the intrusion of a liquid evenwhen a liquid is disposed on the open end of said passage, at least apart of the whole length of said passage being formed to run in adirection not directly axially of the aforesaid supporting member.

In the accompanying drawings which illustrate this invention, FIG. 1 isa sectional view of a transfusion set which is equipped with the airintroduction device of this invention;

FIGS. 2a and 2b are sectional views respectively of two embodimentswhich are provided with hollow needles;

FIGS. 3a to 3e are perspective views respectively of the variousembodiments of the piece to be fitted inside the supporting member;

FIG. 3 is a sectional view taken along line f of FIG. 3e;

FIGS. 4a to 4d are sectional views respectively of the severalembodiments of the air introduction device of this invention; and

FIG. 5 is a sectional view of the conventional prior art transfusionset.

In general, a transfusion set is required to have the ability ofinfusing into the body of man 500- cc. of the liquid to be transfused,within a period of from 30 minutes, to a maximum of 60 minutes. Theconventional prior.

art transfusion set, as shown in FIG. 5, is arranged so as to be able tomeet this demand by a setup wherein a hollow air introduction needle 5supported by a cylindrical supporting member 4 is piercingly passedthrough from the outside of a stopper 3 and the top of the needle 5 ispositioned inside a glass tube 6 for introducing air. Thus, air

' is introduced from the outside via the hollow needle 5 into a space 7which exists above a liquid 1 to be transfused in a vessel 2 for holdingthe liquid, with the consequence that owing to the pressure of the airthe liquid 1 is infused into the body of man from a hollow liquiddischarge needle 8 via a dropping tube 9 and a hollow infusion needle10.

The air introduction device for use in a transfusion set, in accordancewith this invention, differs over the prior art in that it has dispensedwith the use of the glass tube 6 for introducing air, this beingaccomplished by working out a special means in connection with thecylindrical supporting member 4 equipped with the hollow needle 5 forintroducing air, as used in the conventional transfusion set. As aresult, the drawbacks of the conventional transfusion set, ashereinbefore noted, have been improved upon.

FIG. 1 illustrates a transfusion set which has been equipped with theair introduction device of this invention. This device, which consistsof a cylindrical supporting member 4 equipped with a hollow needle 5 forintroducing air, has a. special piece 11 fitted inside the cylindricalsupporting member. The air introduction device shown in FIG. 1 is thesame as the one shown on an enlarged scale in FIG. 4a, which will bedescribed more fully hereinafter. Hollow needle 5 is fitted so that itstip pierces a stopper 3 and is positioned in the liquid 1 to betransfused. The other reference numerals used in FIG. 1, i.e., 2, 7, 8,9 and 10 refer to the same parts as its counterparts in FIG. 5.

The air introduction device of this invention is made up of threemembers consisting of the hollow needle 5 for introducing air, thecylindrical supporting member 4 for supporting said hollow needle, andthe piece 11 to be fitted inside said supporting member. As shOWn inFIG. 2a, the needle 5 is hollowed to form an air passage communicatingwith the inside of the cylindrical supporting member 4 whose bottom endis open but having a transversely disposed top wall or ceiling 12 at itsupper end, the base of the needle being supported by this ceiling. Piece11, which is fitted into the inside of the aforesaid supporting memberspaced apart from the inner surface of the foregoing ceiling, is forforming a confined air passage between the aforesaid space and the openend of the supporting member. FIGS. 3:: to 3 illustrate the differentembodiments thereof. For example, the piece 11 shown in FIG. 3a consistsof a cylindrical block having an outside diameter substantially the sameas the inside diameter of the supporting member 4, in which has beenprovided a helical grooved duct 13 from one end surface S; to theopposite end surface S When this block is inserted in the supportingmember 4 in such a manner that a space a is formed, as shown in FIG. 4a,a tunnel 14 connecting the aforesaid space a and the open end of thesupporting member 4 is formed between the inner periphery of saidsupporting member 4 and the outer periphery of said block 11. Thistunnel 14 is the confined air passage as herein referred to.

. The confined air passage can be likewise formed by fitting any of thepieces 11 shown in FIGS. 3b to 3d inside the supporting member shown ineither FIG. 2a or 2b.

, The piece shown in FIG. 3b, which consists of a cylindrical block 11having an outer diameter substantially equal to the inner diameter ofthe supporting member 4, is provided with a duct 15 between one endsurface S and the outer peripheral side of the block, piercing theinterior of said block, which duct then connects from its block 11 aboutthe top and bottom ends thereof. As a modification of this embodiment,it is also possible to provide one or more screw portions about thecylindrical trunk portion 20 which is not provided with screws, as shownin FIG. 30. Further, this piece may also be one in which the trunkportion 20 and one of the screw portions 19 have been cut away, i.e.,one consisting of only the screw portion 18. In order to prevent damageto the inner surface of the supporting member 4 when fitting this typeof piece therein, it is preferred that the ridges of the screw threadsbe rounded. It can be readily understood that when these piecesillustrated in FIGS. 3b and 3c are fitted inside the foregoingsupporting member shown in FIG. 2a a confined air passage is formed asin the case with the aforesaid piece shown in FIG. 3a. FIG. 4billustrates the instance where the piece 11 of FIG. 30 has been fittedinside the supportingmember 4 of FIG. 2a. As in the case with theinstance shown in FIG. 4a, a is the space and 14 is the tunnel. Piece 11shown in FIG. 3d is simply a cylindrical block. When this is fittedinside a supporting member 4 provided with a female screw 21 in itsinner surface as shown in FIG. 2b, a tunnel 14 similar to that shown inFIG. 4b is formed, as shown in FIG. 40. i

The confined air passage according to this invention must be capillaryin character and can also be formed by utilizing a cloth. However, as isreadily understandable from the following description, this cloth mustbe one which possesses air permeability and water repellency but mustnot be water permeable. As this type of cloth, there are available thevarious synthetic textile cloths and the synthetic resin-treated cloths.As can be readilyunderstood, there exist a vast number of complexconfined air passages in these cloths, which pass from one side of thecloth to the other between the yarns which make up the cloth as well asbetween the filaments which compose the yarns. FIGS. 3e and 3 illustrateone embodiment of a piece for forming the confined air passages byutilizing this type of cloth.

Piece 11 of FIG. 32, as shown in FIG. 3f, is made up by clasping theedges of a cloth 31 intimately in between the inner periphery of anouter frame 32 of hollow cylindrical shape having an outer diametersubstantially equal to the inner diameter of a supporting member 4 andwhose two ends are open, and the outer periphery of an inner frame 33 ofhollow cylindrical shape having an outer diameter somewhat smaller thanthe inner diameter of said outer frame 32 and whose two ends arelikewise open. When the piece 11 is fitted inside the supporting member4 shown in FIG. 2a, as in the case with the previously describedembodiments, the air introduction device of this invention, as shown inFIG. 4:1 is formed. In FIG. 4d, a is the space, 5 is the needle, and 34is a cotton plug for filtration of germs, which is inserted in the openend of the supporting member, as required. This cotton plug is also-usedin the other embodiments of the invention air introduction device, asrequired. The method of fitting to the supporting member the cloth to beused as the confined air passage is not limited to the modes describedabove, but a great number of methods are conceivable. For example, thesimplest method consists of merely fitting the cloth over the open endof the supporting member. I

The confined air passage which has been thus formed must be of such asmall-diametered opening that even though a liquid is disposed on theopening of the passage it does not substantially make entry to saidpassage (presumably on account of the action of surface tension). Ofcourse, if the diameter of the passage is too small, it will not beconsistent with the object of this invention in view of the fact that,as hereinbefore noted, the requirement of a transfusion set is that itbe capable of transfusing 500 cc. of liquid into the body of 'manwithina period of 60 minutes, at the latest. Illustrative dimensions of theair introduction device shown in FIG. 4a which have been found to workwell are presented along with those of the other parts as follows:Length of the hollow needle 5, -30 mm.; diameter of the hollow portionof the hollow needle, 0.4-2 mm.; length of the supporting member 4,10-30 mm.; inside diameter of the supporting member, 2-8 mm.; length ofthe block 11, 5-15 mm.; diameter of the block, 2-8 mm.; number of turnsabout the outer periphery of the block of the grooved duct 13, 2-3;diameter of the tunnel 14 (i.e. the depth of the grooved duct 13), 0.2-1mm.; height of the space a, 0.5-4 mm. The dimensions of the parts in thecase of the embodiments illustrated in FIGS. 4b and 4c are also aboutthe same. In the embodiment shown in FIG. 4c, the effective diameter ofthe cloth, i.e. the inner diameter of the inner frame 33 is convenientlyfrom 1.4 mm. to 3.5 mm., and when a raincoat material composed ofpolyamide is used, 500 cc. of the liquid to be transfused can be infusedin 2-3 minutes.

Although the air introduction device of this invention is not to berestricted by any theories, its functional mechanism is conceived to beas follows: When the invention air introduction device along with theconventional liquid discharge needle 8, dropping tube 9 and liquidinfusion needle 10'is fitted as hereinbefore described, to the vessel 2containing the liquid 1 to be transfused, leaving a space of normalatmospheric pressure at the top, and then inverted, the liquid 1 flowsdown at once to the dropping tube 9 via the liquid discharge needle 8 aswell as to the space a inside the supporting member 4 via the hollowneedle 5, as a result of the pressure of the space 7 and the weight ofthe liquid 1. Lagging somewhat after this downfiow, the pressure in thespace 7 inside the vessel 2 becomes reduced, and hence the downfiowstops temporarily. However, nearly simultaneously outside air is suckedby the action of this reduced pressure into the vessel 2 through theconfined air passage formed in and/or by the block 11. Consequently, thespace 7 inside the vessel 2 reverts to normal atmospheric pressure, andthe downfiow of the liquid to the dropping tube 9 is resumed. The liquidcan thus be steadily infused into the body of man presumably by arepetition of a phenomenon such as described.

Space a in the subject air introduction device is very important andapparently serves as a buffer zone, without which a clogging of theconfined air passage would occur to prevent the smooth infusion of theliquid into the body of man. In the several embodiments of the inventionair introduction device described hereinbefore, the confined air passageis disposed such that it runs in directly and non-parallel to the axisof the supporting member along its entire length, being either ofmeandrous configuration (the blocks in FIGS. 4a-4c) or of complexirregular configuration (the cloth of FIG. 4d). While this is due tosome physical reason, the blockading of the passage can be effectivelyachieved by the various means as illustrated in the hereinbeforedescribed embodiments, to a satisfactory degree even though the wholelength of the confined air passage is not formed deviating from the axisof the supporting member, but by just forming a part of the whole lengthof the supporting member in deviation from the axis of the supportingmember.

By use of the afore-described air introduction device of this invention,it is not necessary to use a complicated type of vessel for the liquidwherein a glass tube for introducing air is provided inside the vessel,as in the conventional transfusion set. Hence, a simple vessel of theusual type will sufiice, and thus all the problems from the standpointof the manufacture of the vessel as well as its sanitary management canbe eliminated. Moreover, since the piece which is fitted in said airintroduction device can be readily fabricated from synthetic resin,metal or cloth, it is inexpensive. Thus, when the over-all cost of thetransfusion set is considered, the set equipped with applicantsinvention air introduction device can be made available at a cost muchless than that of the conventional set.

As in the conventional transfusion set, it is the usual practice inapplicants novel device to assemble it along with the separate parts ofthe set, i.e., the liquid discharge needle, the dropping tube, liquidinfusion needle and the vessel for the liquid, into a complete setimmediately prior to carrying out the transfusion. However, ifcircumstances require, it is also possible to store the vessel in theform in which the subject air introduction device is inserted in advancein the stopper of the vessel. In this case, however, it is desirable toexercise such care as to place a cap over the open end of the supportingmember to ensure that the intrusion of foreign matter into the vesseland the outflow of the liquid therefrom are prevented.

What is claimed is:

1. An air introduction device for a transfusion set comprising incombination:

(a) a supporting member of generally hollow cylindrical form whosebottom end is open but whose top end is provided with an integraltransverse top wall;

(b) a needle whose inside is hollow, said hollow portion being an airpassage which communicates with the inside of said supporting member,said needle having one end supported by means of said top wall andprotruding upwardly above said supporting member axially thereof;

(c) and a solid piece of shorter length than said supporting memberfitted inside said supporting member in spaced relation fromthe innersurface of said top wall, said solid piece being of non-fibrous andnon-porous character, and having a cylindrical shape and an outerdiameter substantially the same as the inner diameter of saidcylindrical supporting member, said cylindrical block having a groovedduct of helical configuration about its periphery starting at one endsurface of said block and terminating at the other end surface thereof,the inner peripheral wall of said supporting member and said groovedduct forming an indirect confined air passage for effectingcommunication between the space formed above said block and the openbottom end of said supporting member; and

(d) said air passage having a small cross-sectional area and beingcapillary in character as to be capable of substantially preventing theintrusion of a liquid, even when a liquid is disposed on the open end ofsaid passage, at least a part of the whole length of said passage beingformed to run in a tortuous indirect path other than directly axially ofsaid supporting member.

2. An air introduction device for a transfusion set comprising incombination:

(a) a supporting member of generally hollow cylindrical form whosebottom end is open but whose topl end is provided with an integraltransverse top wa l;

(b) a needle whose inside is hollow, said hollow portion being an airpassage which communicates with the inside of said supporting member,said needle having one end supported by means of said top wall andprotruding upwardly above said supporting member axially thereof;

(c) and a solid piece of shorter length than said supporting memberfitted inside said supporting member in spaced relation from the innersurface of said top wall, said solid piece being of non-fibrous andnon-porous character, and having a cylindrical shape and an outerdiameter substantially the same as the inner diameter of saidcylindrical supporting member, said cylindrical block having a helicalduct passing partially through and around said block and forming anindirect confined air passage for effecting communication between thespace formed above said block and the open bottom of said supportingmember, said duct. starting at one end surface of the block andterminating in the outer peripheral References Cited UNITED STATESPATENTS 2,081,525 5/1937 Berman 215-79 Pierce 220-44 Ryanet al. 215-56Hencken 137-197 Nesset et a1 128-214 Morrisey et al. 128-214 Bujan .s55-417 Wehle et a1. 220-44 Burke 128-214 DALTONLTRULUCK,PriniaryExaininer v

